A date-time without a time-zone in an arbitrary chronology, intended
for advanced globalization use cases.

Most applications should declare method signatures, fields and variables
as LocalDateTime, not this interface.

A ChronoLocalDateTime is the abstract representation of a local date-time
where the Chronology chronology, or calendar system, is pluggable.
The date-time is defined in terms of fields expressed by TemporalField,
where most common implementations are defined in ChronoField.
The chronology defines how the calendar system operates and the meaning of
the standard fields.

When to use this interface

The design of the API encourages the use of LocalDateTime rather than this
interface, even in the case where the application needs to deal with multiple
calendar systems. The rationale for this is explored in detail in ChronoLocalDate.

Ensure that the discussion in ChronoLocalDate has been read and understood
before using this interface.

Implementation Requirements:

This interface must be implemented with care to ensure other classes operate correctly.
All implementations that can be instantiated must be final, immutable and thread-safe.
Subclasses should be Serializable wherever possible.

Method Detail

timeLineOrder

Gets a comparator that compares ChronoLocalDateTime in
time-line order ignoring the chronology.

This comparator differs from the comparison in compareTo(java.time.chrono.ChronoLocalDateTime<?>) in that it
only compares the underlying date-time and not the chronology.
This allows dates in different calendar systems to be compared based
on the position of the date-time on the local time-line.
The underlying comparison is equivalent to comparing the epoch-day and nano-of-day.

from

This obtains a local date-time based on the specified temporal.
A TemporalAccessor represents an arbitrary set of date and time information,
which this factory converts to an instance of ChronoLocalDateTime.

The conversion extracts and combines the chronology and the date-time
from the temporal object. The behavior is equivalent to using
Chronology.localDateTime(TemporalAccessor) with the extracted chronology.
Implementations are permitted to perform optimizations such as accessing
those fields that are equivalent to the relevant objects.

This method matches the signature of the functional interface TemporalQuery
allowing it to be used as a query via method reference, ChronoLocalDateTime::from.

isSupported

This checks if the specified field can be queried on this date-time.
If false, then calling the range,
get and with(TemporalField, long)
methods will throw an exception.

The set of supported fields is defined by the chronology and normally includes
all ChronoField date and time fields.

If the field is not a ChronoField, then the result of this method
is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor)
passing this as the argument.
Whether the field is supported is determined by the field.

isSupported

This checks if the specified unit can be added to or subtracted from this date-time.
If false, then calling the plus(long, TemporalUnit) and
minus methods will throw an exception.

The set of supported units is defined by the chronology and normally includes
all ChronoUnit units except FOREVER.

If the unit is not a ChronoUnit, then the result of this method
is obtained by invoking TemporalUnit.isSupportedBy(Temporal)
passing this as the argument.
Whether the unit is supported is determined by the unit.

with

Returns an adjusted object of the same type as this object with the adjustment made.

This adjusts this date-time according to the rules of the specified adjuster.
A simple adjuster might simply set the one of the fields, such as the year field.
A more complex adjuster might set the date to the last day of the month.
A selection of common adjustments is provided in
TemporalAdjusters.
These include finding the "last day of the month" and "next Wednesday".
The adjuster is responsible for handling special cases, such as the varying
lengths of month and leap years.

with

Returns an object of the same type as this object with the specified field altered.

This returns a new object based on this one with the value for the specified field changed.
For example, on a LocalDate, this could be used to set the year, month or day-of-month.
The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is
a date representing the 31st January, then changing the month to February would be unclear.
In cases like this, the field is responsible for resolving the result. Typically it will choose
the previous valid date, which would be the last valid day of February in this example.

plus

Returns an object of the same type as this object with an amount added.

This adjusts this temporal, adding according to the rules of the specified amount.
The amount is typically a Period but may be any other type implementing
the TemporalAmount interface, such as Duration.

plus

Returns an object of the same type as this object with the specified period added.

This method returns a new object based on this one with the specified period added.
For example, on a LocalDate, this could be used to add a number of years, months or days.
The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is
a date representing the 31st January, then adding one month would be unclear.
In cases like this, the field is responsible for resolving the result. Typically it will choose
the previous valid date, which would be the last valid day of February in this example.

minus

Returns an object of the same type as this object with an amount subtracted.

This adjusts this temporal, subtracting according to the rules of the specified amount.
The amount is typically a Period but may be any other type implementing
the TemporalAmount interface, such as Duration.

minus

Returns an object of the same type as this object with the specified period subtracted.

This method returns a new object based on this one with the specified period subtracted.
For example, on a LocalDate, this could be used to subtract a number of years, months or days.
The returned object will have the same observable type as this object.

In some cases, changing a field is not fully defined. For example, if the target object is
a date representing the 31st March, then subtracting one month would be unclear.
In cases like this, the field is responsible for resolving the result. Typically it will choose
the previous valid date, which would be the last valid day of February in this example.

query

This queries this date-time using the specified query strategy object.
The TemporalQuery object defines the logic to be used to
obtain the result. Read the documentation of the query to understand
what the result of this method will be.

atZone

This returns a ChronoZonedDateTime formed from this date-time at the
specified time-zone. The result will match this date-time as closely as possible.
Time-zone rules, such as daylight savings, mean that not every local date-time
is valid for the specified zone, thus the local date-time may be adjusted.

The local date-time is resolved to a single instant on the time-line.
This is achieved by finding a valid offset from UTC/Greenwich for the local
date-time as defined by the rules of the zone ID.

In most cases, there is only one valid offset for a local date-time.
In the case of an overlap, where clocks are set back, there are two valid offsets.
This method uses the earlier offset typically corresponding to "summer".

In the case of a gap, where clocks jump forward, there is no valid offset.
Instead, the local date-time is adjusted to be later by the length of the gap.
For a typical one hour daylight savings change, the local date-time will be
moved one hour later into the offset typically corresponding to "summer".

toEpochSecond

Converts this date-time to the number of seconds from the epoch
of 1970-01-01T00:00:00Z.

This combines this local date-time and the specified offset to calculate the
epoch-second value, which is the number of elapsed seconds from 1970-01-01T00:00:00Z.
Instants on the time-line after the epoch are positive, earlier are negative.

This default implementation calculates from the epoch-day of the date and the
second-of-day of the time.

compareTo

Compares this date-time to another date-time, including the chronology.

The comparison is based first on the underlying time-line date-time, then
on the chronology.
It is "consistent with equals", as defined by Comparable.

For example, the following is the comparator order:

2012-12-03T12:00 (ISO)

2012-12-04T12:00 (ISO)

2555-12-04T12:00 (ThaiBuddhist)

2012-12-05T12:00 (ISO)

Values #2 and #3 represent the same date-time on the time-line.
When two values represent the same date-time, the chronology ID is compared to distinguish them.
This step is needed to make the ordering "consistent with equals".

If all the date-time objects being compared are in the same chronology, then the
additional chronology stage is not required and only the local date-time is used.

isAfter

Checks if this date-time is after the specified date-time ignoring the chronology.

This method differs from the comparison in compareTo(java.time.chrono.ChronoLocalDateTime<?>) in that it
only compares the underlying date-time and not the chronology.
This allows dates in different calendar systems to be compared based
on the time-line position.

This default implementation performs the comparison based on the epoch-day
and nano-of-day.

Parameters:

other - the other date-time to compare to, not null

Returns:

true if this is after the specified date-time

isBefore

Checks if this date-time is before the specified date-time ignoring the chronology.

This method differs from the comparison in compareTo(java.time.chrono.ChronoLocalDateTime<?>) in that it
only compares the underlying date-time and not the chronology.
This allows dates in different calendar systems to be compared based
on the time-line position.

This default implementation performs the comparison based on the epoch-day
and nano-of-day.

Parameters:

other - the other date-time to compare to, not null

Returns:

true if this is before the specified date-time

isEqual

Checks if this date-time is equal to the specified date-time ignoring the chronology.

This method differs from the comparison in compareTo(java.time.chrono.ChronoLocalDateTime<?>) in that it
only compares the underlying date and time and not the chronology.
This allows date-times in different calendar systems to be compared based
on the time-line position.

This default implementation performs the comparison based on the epoch-day
and nano-of-day.

Parameters:

other - the other date-time to compare to, not null

Returns:

true if the underlying date-time is equal to the specified date-time on the timeline